1. Parent Material and Soil Formation Created by Jim Ippolito & Mike Hanna College of Agricultural Sciences Colorado State University
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2. a discussion of the type of soil parent material1 2 8 3 6 5 7
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a discussion of the type
of soil parent material 4
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3. Type of Parent Material: Colluvium Mode of Transportation: Gravity
Colluvium Photo:
Source:
Type of Parent Material: Colluvium
Mode of Transportation: Gravity
Degree of Sorting by Particle Size: Low
Additional Information: The term colluvium classifies parent
material transported by gravity. Colluvium is made up of a
heterogeneous mixture of boulders, rocks, pebbles, and soil
from upslope areas. Thus the degree of particle sorting is
low.
Background Photo Source: Jim Ippolito; Northern boundary of Rocky Mountain National Park, Colorado

4. terminal moraine Type of Parent Material: Glacial Till
Glacial Till Photo Source: Peter Fletcher
terminal moraine
Type of Parent Material: Glacial Till
Mode of Transportation: Ice
Degree of Sorting by Particle Size: Low
Additional Information: Parent material
transported by ice is called glacial till. This parent material is found where glaciers have deposited material, such as in terminal or lateral moraines. Ice is a poor sorter of particles, and thus glacial till contains everything from the smallest clay-sized fraction to rocks, pebbles, and boulders.
Background Photo Source: Jim Ippolito; Northern boundary of Rocky Mountain National Park, Colorado

5. Type of Parent Material: Tephra Mode of Transportation: Wind
Background Photo Source:
Type of Parent Material: Tephra
Mode of Transportation: Wind
Degree of Sorting by Particle Size: High
Additional Information: Parent material
transported via volcanic ejecta is called
tephra. The mode of transportation is
wind. Wind is a good sorter of particles.
Larger particles tend to bounce on the
Earth’s surface while smaller particles are
transported greater distances.
Soil developed from volcanic ejecta.
Soil Profile Source:

6. Type of Parent Material: Loess or Aeolian Mode of Transportation: Wind
Aeolian Photo:
Source: Dr. Paul McDaniel;
Type of Parent Material: Loess or Aeolian Mode of Transportation: Wind
Degree of Sorting by Particle Size: High
Additional Information: Parent material
transported by wind is called loess or aeolian. Wind is a good sorter of particles. Larger particles tend to bounce on the Earth’s surface while smaller particles are transported greater distances.
Background Photo Source:

7. Type of Parent Material: Alluvium Mode of Transportation: Water
Degree of Sorting by Particle Size: High
Additional Information: Parent material
transported by flowing water (streams, rivers) is called alluvium. Water is a good sorter of soil particles. Larger particles (i.e. sands) settle out of water first, and smaller particles (i.e. clays) settle out of water last. Thus, you tend to find sand-sized particles closer to the water source and clay-sized particles further away.
Soil developed from alluvium.
Source:

8. Type of Parent Material: Lacustrine Mode of Transportation: Lake
Degree of Sorting by Particle Size: High
Additional Information: The term lacustrine
classifies parent material transported by a
lake. Water is acting on the parent material
and thus there is a high degree of particle
sorting.
Lacustrine Deposit Profile Source: NRCS staff,

9. Type of Parent Material: Marine Mode of Transportation: Ocean
Degree of Sorting by Particle Size: High
Additional Information: The term “marine” classifies
parent material transported by oceans. Water is
acting on the parent material and thus there is a
high degree of particle sorting.
Soil Profile Source:

10. Degree of Sorting by Particle Size: Low
Soil Profile Source:
Type of Parent Material: Residual or Residuum. Mode of Transportation: In place; none.
Degree of Sorting by Particle Size: Low
Additional Information: The terms residual or residuum classify parent material formed in place (i.e. non-transported). The degree of sorting is low because no other factors have influenced soil movement.